@article{IVM_1972_4_a5,
     author = {A. L. Garkavi},
     title = {A~certain criterion for a~$K$-system of continuous functions},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {55--59},
     publisher = {mathdoc},
     number = {4},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1972_4_a5/}
}